Influence of the Preparation Method on Catalytic Properties of Pd/TiO2 Catalysts in the Reaction of Partial Oxidation of Methanol

Palladium supported TiO2 catalysts (2 %wt. of Pd) were prepared by different methods and studied in the gas phase reaction of partial oxidation of methanol. A comparative study of classical methods of preparation with those prepared in liquid phase was done. The catalysts were characterized by different methods such as: ICP, XRD, XPS, H2- chemisorption, N2-physisorption and TEM. The results showed that the preparation method changes the catalytic properties of the materials: both catalysts prepared by chemical reduction with hydrazine (aqueous and microemulsion) showed better catalytic performances than their classical counterparts (wet impregnation and sol gel). The activity of the catalysts is strongly influenced by the palladium particle size which seems to play a crucial role in the reaction mechanism.